FT -IR and Raman spectroscopic studies of xAg2O-(100-x)[3B2O3·As2O3] glass system

Abstract

Structural analysis of xAg20(100-x)[3B 2 O 3 ·As 2 O 3 ] glass system, with 0 ≤ x ≤ 10 mol%, was performed by means of FT - IR and Raman spectroscopies. The purpose of this work is to investigate the structural changes that appear in the 3B 2 O3·As 2 O 3 glass matrix with the addition and increasing of silver ions content. Boroxol rings, pyro-, ortho-, di-, tri-, tetraand penta-borate groups and structural units characteristic to As 2 O 3 were found in the structure of the studied glasses. At small silver oxide content the predominant structural units are those in which boron is three-fold coordinated. For higher silver oxide concentrations (x ≥ 5 mol%) the number of four-fold coordinated boron units is increasing. The changes in the A r = A 4 /A 3 (A 4 and A 3 reflect the relative amount of tetrahedral (BO 4 and B∅ - 4 ) and triangular (BO 3 and BO 2 O - ) borate species) ratio also shows the fact that silver oxide influence the boron coordination number. The Raman analysis leads to similar conclusions as FT- IR measurements.